The major guideline groups recommend a combination of a 5-HT3 receptor antagonist, dexamethasone and aprepitant ('triple therapy') for treatment categorized as highly emetogenic. Recent data suggest that, although classified as highly emetogenic, palonosetron may provide very good control of emesis for CHOP and ABVD. Guidelines have not made firm recommendations for highly emetogenic chemotherapy administered over several days or stem cell transplant preparative regimens due to the lack of published randomized trials. Although well tolerated and effective, many patients receive suboptimal antiemetic therapy that includes aprepitant.